Halloween is officially over and various rock/metal artists have taken to social media to share pictures of the costumes they wore this year. You can check out a bunch of those posts below: Taylor Momsen (The Pretty Reckless): Amy Lee (Evanescence): Spencer Charnas (Ice Nine Kills): Matt Heafy (Trivium): Nikki Sixx (Mötley Crüe): Robert Trujillo…